KeJi

KeJi is a small Chrome / Edge extension for students who learn from video. It helps you take notes while a lecture plays, without leaving the page. Version 0.4.0 is in testing. It works on Windows and Mac, in Chrome and Edge (not Safari or Firefox).

What it does

KeJi does one basic job. You take notes while a video plays, and every note remembers the exact second you wrote it. Later, click the note and the video goes back to that second. You can search your notes, mark the ones to review, and export them as Markdown.

Features

• A new look (0.4.0). Warm cream and corgi orange, in light or dark to match your system. Every note is a paw print on the progress bar: click a paw to jump back. Settings sit behind the gear. See it on the KeJi page.
• Three layouts. Show KeJi as the usual popup, as a floating panel you can drag, resize and collapse, or in the browser's side panel, where the page shrinks to make room and the panel never covers the video.
• Jump back to the second. Click a note's timestamp or "Open page" and the video returns to the moment you wrote it, even inside an embedded player. If the page is closed, it reopens and waits for the video. It never starts playing by itself.
• Pauses while you type, and resumes after you save. You can turn this off in settings.
• A speed slider from 0.5× to 2×, with a 1× reset button.
• Notes in fullscreen with a shortcut. The small note box can be dragged out of the way.
• Notes grouped by video. Exported Markdown keeps the grouping, and the timestamps are links.
• A desktop alert when a lesson ends, right-click a selected question to save it, and an English or Chinese interface.

It never fakes watch time or completion, gets around a platform's sign-in, answers questions, or asks for a password. Everything is stored only in your browser.

Install (about 3 minutes)

1. Download the zip with the button above and unzip it. On Mac, double-click the zip in Finder. You get a folder named keji. Move it somewhere permanent, such as Documents, because the extension stops working if the folder is deleted.
2. Open the extensions page. In Chrome type chrome://extensions in the address bar. In Edge type edge://extensions.
3. Turn on Developer mode: top right in Chrome, left side in Edge.
4. Click Load unpacked (Edge: "Load unpacked"), and choose the keji folder. Choose the folder itself, not a file inside it.
5. Click the puzzle icon in the toolbar and pin KeJi.
6. Reload any course page that was already open.

The browser may say "Disable developer mode extensions" each time it starts. Choose Keep.

To upgrade, unzip the new version over the old folder, then click the reload arrow on the KeJi card. Your notes are kept.

Set up the shortcuts

Open chrome://extensions/shortcuts (Edge: edge://extensions/shortcuts) and look at the KeJi section. On Mac, Alt is the Option key.

• Open the KeJi panel: Alt+Shift+C (Mac: Option+Shift+C)
• Play or pause: Alt+Shift+K
• Take a note on the page: Alt+Shift+N
• Speed up or slow down by 0.25×: no default, set your own

If a shortcut shows "Not set" or does nothing, click the box next to it and press the keys you want. If another extension already uses the keys, pick different ones. Set the scope to "In Chrome" so it works on every page.

How to use it

1. Open a lecture. Click the KeJi icon (or press Alt+Shift+C). It shows the video status, the speed slider and a box for notes. To change the layout, click the gear and choose Layout: Popup, Floating or Side. The side panel keeps the video uncovered; the floating panel starts on the right side of the page and remembers where you put it.
2. Type a note and click Save. The note keeps the video's current time. While you type, the video pauses. After you save, it continues.
3. In fullscreen, press Alt+Shift+N. A small note box appears on the video. Enter saves, Shift+Enter starts a new line, Esc closes it.
4. To review, open the KeJi panel and click the list icon next to the gear (All notes). Notes are grouped by video. Click a time (like 12:34) or "Open page" to go back to that second.
5. "Export as Markdown" saves your notes as a file. YouTube links jump to the second. On other sites, the link ends with #kejit=seconds and jumps only in a browser that has KeJi installed.
6. Settings (the gear): layout, lesson-end alerts, remembering your speed per site, pause while typing, search engine, and language (Auto / 中文 / English).

If something does not work

• "No video found" on the panel: reload the page, then click the video once so it appears.
• Nothing happens after installing: the page was open before you installed. Reload it.
• A shortcut does nothing: set it on the shortcuts page above.
• The jump lands in the wrong place: some platforms restore their own position after loading. Click the time again.

So far it has only been checked on test pages, not on a real course platform. The side panel and floating panel in particular have not yet been tried on a real video site or in Edge. If your course player has no speed control of its own, do not use the speed slider and turn off "Remember my speed".